I use both at different times.
Desktop always has much more potential in terms of power than a laptop at a given time.
Modifying desktop are also easier. It is cheaper and better.
They are also easy to fix and upgrade for the hardware part. It's just that good.
But Laptops are portable - an advantage with good weights even if only one.
They really aren't good for much else, except for saving space if that counts.
It's better for people with much less of a need for raw power and for people who just want a PC to use.
But I got both anyways. The desktop is totally mine, and the laptop is shared, though I am the one to use it most of the time.
So my desktop serves as my real personal storage.